Rage.
Sometimes that's all you have left of your loved ones, your friends, your family. Their bodies are gone, either buried in a poorly marked grave or scattered to the wind, depending on how they fell. Sometimes they're still walking, but that doesn't really count.
But the rage lives on. That surge you get when you think of them. When you think of them fighting, dying, pleading for life. It's that moment when you bare your own teeth and let the hate flow, giving you strength, sharpening your senses.
It's what allows you to survive when others die.
Those who survived but didn't lose anyone will never understand that it's our rage that keeps us going, our rage that makes the difference.